summaryrefslogtreecommitdiff
path: root/linux/src/include/asm-i386/segment.h
blob: 6052ad459f558697b8f9cb88e9ba282cb910ab78 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
#ifndef _ASM_SEGMENT_H
#define _ASM_SEGMENT_H

#define KERNEL_CS	0x10
#define KERNEL_DS	0x18

#define USER_CS		0x23
#define USER_DS		0x2B

#ifndef __ASSEMBLY__

/*
 * Uh, these should become the main single-value transfer routines..
 * They automatically use the right size if we just have the right
 * pointer type..
 */
#define put_user(x,ptr) __put_user((unsigned long)(x),(ptr),sizeof(*(ptr)))
#define get_user(ptr) ((__typeof__(*(ptr)))__get_user((ptr),sizeof(*(ptr))))

/*
 * This is a silly but good way to make sure that
 * the __put_user function is indeed always optimized,
 * and that we use the correct sizes..
 */
extern int bad_user_access_length(void);

/*
 * dummy pointer type structure.. gcc won't try to do something strange
 * this way..
 */
struct __segment_dummy { unsigned long a[100]; };
#define __sd(x) ((struct __segment_dummy *) (x))
#define __const_sd(x) ((const struct __segment_dummy *) (x))

static inline void __put_user(unsigned long x, void * y, int size)
{
	switch (size) {
		case 1:
			__asm__ ("movb %b1,%%fs:%0"
				:"=m" (*__sd(y))
				:"iq" ((unsigned char) x), "m" (*__sd(y)));
			break;
		case 2:
			__asm__ ("movw %w1,%%fs:%0"
				:"=m" (*__sd(y))
				:"ir" ((unsigned short) x), "m" (*__sd(y)));
			break;
		case 4:
			__asm__ ("movl %1,%%fs:%0"
				:"=m" (*__sd(y))
				:"ir" (x), "m" (*__sd(y)));
			break;
		default:
			bad_user_access_length();
	}
}

static inline unsigned long __get_user(const void * y, int size)
{
	unsigned long result;

	switch (size) {
		case 1:
			__asm__ ("movb %%fs:%1,%b0"
				:"=q" (result)
				:"m" (*__const_sd(y)));
			return (unsigned char) result;
		case 2:
			__asm__ ("movw %%fs:%1,%w0"
				:"=r" (result)
				:"m" (*__const_sd(y)));
			return (unsigned short) result;
		case 4:
			__asm__ ("movl %%fs:%1,%0"
				:"=r" (result)
				:"m" (*__const_sd(y)));
			return result;
		default:
			return bad_user_access_length();
	}
}

static inline void __generic_memcpy_tofs(void * to, const void * from, unsigned long n)
{
    __asm__ volatile
	("	cld
		push %%es
		push %%fs
		cmpl $3,%0
		pop %%es
		jbe 1f
		movl %%edi,%%ecx
		negl %%ecx
		andl $3,%%ecx
		subl %%ecx,%0
		rep; movsb
		movl %0,%%ecx
		shrl $2,%%ecx
		rep; movsl
		andl $3,%0
	1:	movl %0,%%ecx
		rep; movsb
		pop %%es"
	:"=abd" (n)
	:"0" (n),"D" ((long) to),"S" ((long) from)
	:"cx","di","si");
}

static inline void __constant_memcpy_tofs(void * to, const void * from, unsigned long n)
{
	switch (n) {
		case 0:
			return;
		case 1:
			__put_user(*(const char *) from, (char *) to, 1);
			return;
		case 2:
			__put_user(*(const short *) from, (short *) to, 2);
			return;
		case 3:
			__put_user(*(const short *) from, (short *) to, 2);
			__put_user(*(2+(const char *) from), 2+(char *) to, 1);
			return;
		case 4:
			__put_user(*(const int *) from, (int *) to, 4);
			return;
		case 8:
			__put_user(*(const int *) from, (int *) to, 4);
			__put_user(*(1+(const int *) from), 1+(int *) to, 4);
			return;
		case 12:
			__put_user(*(const int *) from, (int *) to, 4);
			__put_user(*(1+(const int *) from), 1+(int *) to, 4);
			__put_user(*(2+(const int *) from), 2+(int *) to, 4);
			return;
		case 16:
			__put_user(*(const int *) from, (int *) to, 4);
			__put_user(*(1+(const int *) from), 1+(int *) to, 4);
			__put_user(*(2+(const int *) from), 2+(int *) to, 4);
			__put_user(*(3+(const int *) from), 3+(int *) to, 4);
			return;
	}
#define COMMON(x) \
__asm__("cld\n\t" \
	"push %%es\n\t" \
	"push %%fs\n\t" \
	"pop %%es\n\t" \
	"rep ; movsl\n\t" \
	x \
	"pop %%es" \
	: /* no outputs */ \
	:"c" (n/4),"D" ((long) to),"S" ((long) from) \
	:"cx","di","si")

	switch (n % 4) {
		case 0:
			COMMON("");
			return;
		case 1:
			COMMON("movsb\n\t");
			return;
		case 2:
			COMMON("movsw\n\t");
			return;
		case 3:
			COMMON("movsw\n\tmovsb\n\t");
			return;
	}
#undef COMMON
}

static inline void __generic_memcpy_fromfs(void * to, const void * from, unsigned long n)
{
    __asm__ volatile
	("	cld
		cmpl $3,%0
		jbe 1f
		movl %%edi,%%ecx
		negl %%ecx
		andl $3,%%ecx
		subl %%ecx,%0
		fs; rep; movsb
		movl %0,%%ecx
		shrl $2,%%ecx
		fs; rep; movsl
		andl $3,%0
	1:	movl %0,%%ecx
		fs; rep; movsb"
	:"=abd" (n)
	:"0" (n),"D" ((long) to),"S" ((long) from)
	:"cx","di","si", "memory");
}

static inline void __constant_memcpy_fromfs(void * to, const void * from, unsigned long n)
{
	switch (n) {
		case 0:
			return;
		case 1:
			*(char *)to = __get_user((const char *) from, 1);
			return;
		case 2:
			*(short *)to = __get_user((const short *) from, 2);
			return;
		case 3:
			*(short *) to = __get_user((const short *) from, 2);
			*((char *) to + 2) = __get_user(2+(const char *) from, 1);
			return;
		case 4:
			*(int *) to = __get_user((const int *) from, 4);
			return;
		case 8:
			*(int *) to = __get_user((const int *) from, 4);
			*(1+(int *) to) = __get_user(1+(const int *) from, 4);
			return;
		case 12:
			*(int *) to = __get_user((const int *) from, 4);
			*(1+(int *) to) = __get_user(1+(const int *) from, 4);
			*(2+(int *) to) = __get_user(2+(const int *) from, 4);
			return;
		case 16:
			*(int *) to = __get_user((const int *) from, 4);
			*(1+(int *) to) = __get_user(1+(const int *) from, 4);
			*(2+(int *) to) = __get_user(2+(const int *) from, 4);
			*(3+(int *) to) = __get_user(3+(const int *) from, 4);
			return;
	}
#define COMMON(x) \
__asm__("cld\n\t" \
	"rep ; fs ; movsl\n\t" \
	x \
	: /* no outputs */ \
	:"c" (n/4),"D" ((long) to),"S" ((long) from) \
	:"cx","di","si","memory")

	switch (n % 4) {
		case 0:
			COMMON("");
			return;
		case 1:
			COMMON("fs ; movsb");
			return;
		case 2:
			COMMON("fs ; movsw");
			return;
		case 3:
			COMMON("fs ; movsw\n\tfs ; movsb");
			return;
	}
#undef COMMON
}

#define memcpy_fromfs(to, from, n) \
(__builtin_constant_p(n) ? \
 __constant_memcpy_fromfs((to),(from),(n)) : \
 __generic_memcpy_fromfs((to),(from),(n)))

#define memcpy_tofs(to, from, n) \
(__builtin_constant_p(n) ? \
 __constant_memcpy_tofs((to),(from),(n)) : \
 __generic_memcpy_tofs((to),(from),(n)))

/*
 * These are deprecated..
 *
 * Use "put_user()" and "get_user()" with the proper pointer types instead.
 */

#define get_fs_byte(addr) __get_user((const unsigned char *)(addr),1)
#define get_fs_word(addr) __get_user((const unsigned short *)(addr),2)
#define get_fs_long(addr) __get_user((const unsigned int *)(addr),4)

#define put_fs_byte(x,addr) __put_user((x),(unsigned char *)(addr),1)
#define put_fs_word(x,addr) __put_user((x),(unsigned short *)(addr),2)
#define put_fs_long(x,addr) __put_user((x),(unsigned int *)(addr),4)

#ifdef WE_REALLY_WANT_TO_USE_A_BROKEN_INTERFACE

static inline unsigned short get_user_word(const short *addr)
{
	return __get_user(addr, 2);
}

static inline unsigned char get_user_byte(const char * addr)
{
	return __get_user(addr,1);
}

static inline unsigned long get_user_long(const int *addr)
{
	return __get_user(addr, 4);
}

static inline void put_user_byte(char val,char *addr)
{
	__put_user(val, addr, 1);
}

static inline void put_user_word(short val,short * addr)
{
	__put_user(val, addr, 2);
}

static inline void put_user_long(unsigned long val,int * addr)
{
	__put_user(val, addr, 4);
}

#endif

/*
 * Someone who knows GNU asm better than I should double check the following.
 * It seems to work, but I don't know if I'm doing something subtly wrong.
 * --- TYT, 11/24/91
 * [ nothing wrong here, Linus: I just changed the ax to be any reg ]
 */

static inline unsigned long get_fs(void)
{
	unsigned long _v;
	__asm__("mov %%fs,%w0":"=r" (_v):"0" (0));
	return _v;
}

static inline unsigned long get_ds(void)
{
	unsigned long _v;
	__asm__("mov %%ds,%w0":"=r" (_v):"0" (0));
	return _v;
}

static inline void set_fs(unsigned long val)
{
	__asm__ __volatile__("mov %w0,%%fs": /* no output */ :"r" (val));
}

#endif /* __ASSEMBLY__ */

#endif /* _ASM_SEGMENT_H */